Every year there's a few design trends on the web that make their rounds. Some are recognized as good design patterns and persist while others gradually fade out. Thankfully most of these trends are tacky and cringeworthy at worst (web 2.0 rounded glossy buttons anybody?), but every so often there's one that's just so downright awful, so downright evil, that when I cross paths with it I can inevitably be witnessed at public cafes twitching and muttering swear words under my breath.
So why is this bad?
Because good design should make a user's experience as fluid and effortless as possible. We're trained to expect certain differences in website's designs, but at the core of our browsing experience we assume that the way we interact with them will be done in the same manner. When a new feature alters a basic interaction in an unexpected and inconsistent way, it requires heavy concentration from the end user that almost inevitably causes confusion and frustration.
This isn't to say that inertial scrolling is a bad idea in and of itself — Windows could take a cue from OSX on that point — but it's only good when it's done in a way that both feels natural and is implemented system (or potentially application) wide.
I'm all for new features that enhance our experience on the web, even when it's ahead of the curve regarding browser support, but this new trend is definitely not one of them.